1. Field of the Invention
The present invention generally relates to a control device for a direct fuel injection spark ignition engine. More specifically, the present invention relates to a control device that is suitable during cold starting and the like, or when it is necessary to warm up a catalyst for exhaust purification provided to the exhaust channel.
2. Background Information
One example of a direct fuel injection spark ignition engine is disclosed in Japanese Laid-Open Patent Application No. 2000-145510 in which a three-way catalyst is not activated during a cold start and HC is discharged without being reduced in the case of homogenous combustion by intake stroke injection. Thus, in this direct fuel injection spark ignition engine, when the temperature of the engine is detected and the detected temperature is below a prescribed temperature, the air/fuel ratio is adjusted to be leaner than the theoretical air/fuel ratio in the compression stroke, and the fuel is injected.
By performing stratified combustion by compression stroke injection during a cold start, fuel can be prevented from adhering to the cylinder walls, and the HC discharge quantity can be reduced. In addition, the exhaust temperature is increased, so warming up of the catalyst can be accelerated.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved control device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.